Background

In this assignment, you will work with the same suburb surrounding one of the new       stations of stage one of the SRL as you did in Assignments 1. You will work with a        specific intersection close to the station that is defined below based on the last digit of your student ID. See Assignment 1 for additional background information on the       Suburban Rail Loop (SRL).

In your assignment, answers should be preceded by your student ID and intersection/station names.

•   Student ID # ending with 0, 1 or 2 = Cheltenham (SSC 20536 & 21176) Intersection: Bay Road & Nepean Hwy [SCATS ID: 2326]

•   Student ID # ending with 3, 4 or 5 = Clayton (SSC 20566 & 21962) Intersection: Carnish Road & Clayton Road [SCATS ID: 3206]

•   Student ID # ending with 6 or 7 = Glen Waverley (SSC 21006) Intersection: Railway Parade & Kingsway [SCATS ID: 407]

•   Student ID # ending with 8 or 9 = Box Hill (SSC 20312 & 20314)

Intersection: Whitehorse Road & Station Street [SCATS ID: 2206] See Appendix A for details about the intersections and SCATS site.

Task

With the introduction of the SRL station in the proximity of the selected intersection,    pedestrian flows are likely to increase in the area. To accommodate such flows, traffic signals can have adaptative plans that vary based on the rail schedule to improve      pedestrian access/egress close to train departure/arrival times.

Your task will be to design a signal timing plan for the designated intersection that   improves the level of service of pedestrian access to the station (includes a phasing mechanism that protects and gives priority to pedestrians) .

You should define the movements and mode specific volumes based on the attached dataset <traffic_20220517.csv>. Further information about traffic detectors is provided in Appendix A. Calculation explanations and formulas for signal timing design are       provided in the lecture, tutorial, and reading materials of the subject.

Question 1 (5%)

Draw an intersection representation diagram. Label the width of pedestrian crosswalks (if crosswalks do not exist for all approaches, please add them into your intersection),  width of the intersection, road names, and posted traffic speeds for each leg of the      intersection.

Question 2 (5%)

Plot the hourly profile of traffic volumes through the intersection (consider only  relevant detectors). Identify the peak hour and, within the peak hour, the peak 15- minute period.

Question 3 (20%)

Calculate the peak hour volumes and peak 15-minute volumes of traffic at the            existing intersection for each approach-movement by providing an average per-lane value. Clearly label the approach and movement when presenting your results.

Traffic detector volumes are provided for individual lanes. Aggregate all lanes with the same movement and provide an average per lane-volume for each movement (e.g. if Detectors 1, 2, and 3 are all east approach through movements, the average per-lane

Peak Volume Detector 1 + Peak Volume Detector 2 + Peak Volume Detector 3

3

Some lanes will have shared movements (e.g. through/left turn) – make an assumption  regarding the distribution of traffic between these movements (e.g. 80% through, 20%    left turn). Use the traffic data and associated signal detection diagram image provided in Appendix A. Ignore departure lane volumes if present. Some lanes will not have             detectors and associated volumes – these can be assumed relative to other volumes at this intersection. Clearly state your methodology and any assumptions made.

Question 4 (12.5%)

With the Suburban Rail Loop, pedestrian flows for access/egress to the station close to train departure/arrival times should be prioritised. This increase in vulnerable road user movements presents a safety risk at intersections. Identify three phasing mechanisms that reduce pedestrian and turning vehicle conflicts that would be applicable to your     intersection. Select one of these mechanisms to apply to your intersection and discuss their benefits justifying your response with at least one reference.

Question 5 (5%)

Propose a phasing plan based on the composition of traffic volumes identified in             Question 2 and the phasing mechanism to prioritise pedestrians selected in Question 3. Consider whether pedestrian and vehicle turning movements should be protected and   ensure to account for all traffic and pedestrian movements in your phase diagram . Label each phase alphabetically; consistent phase labelling should be carried throughout the  following questions.

Question 6 (12.5%)

Identify the critical movement for each phase. Using this critical movement, calculate the length of the intergreen period for each phase of your cycle. Clearly state any         assumptions you have made.

Question 7 (5%)

Calculate the design flow rate (V) for the critical movement for each phase using the calculated peak hour volumes and peak hour factor from your traffic data.

Question 8 (2.5%)

Calculate the critical flow ratios (V/s) assuming a saturation flow rate (s) of 1900 veh/lane/hour for each phase.

Question 9 (5%)

Calculate the optimum cycle length. Round this value up to the nearest 5 second interval. Calculate the total available green time for the cycle.

N.B. Subtract the intergreen period for each phase from the optimum cycle length to determine the total available green time.

Question 10 (5%)

Allocate the proportion of available green time for each phase using the critical flow      ratios (for each phase) and total available green time previously calculated for the cycle. Assume that the minimum green time for each phase is 7 seconds. Adjust your              available green times for each phase if necessary.

Question 11 (5%)

Draw a phase and signal timing cycle diagram that clearly shows the signal timing         across each phase. Clearly label the intergreen periods (yellow + all-red, assuming all- red = 2 seconds) and green intervals. An example diagram is presented in Appendix B.

Question 12 (10%)

Your phase and signal timing were calculated based on traffic flows and optimising       vehicle throughput. However, your intersection is near an SRL station, so there is a       competing demand for pedestrian movements. Assuming that all crosswalks have the   same pedestrian demand, what is the expected (average) waiting time of a pedestrian  trying to cross the intersection to reach the station? Clearly state your methodology and any assumptions made.

Question 13 (7.5%)

Evaluate your signal plan and briefly discuss whether it is a good solution from the pedestrian’s point of view. Will pedestrians be likely to jaywalk? If so, would the     intergreen times enable safe crossing (jaywalking)?

Appendix A

SCATS SITE 2326

•    Pedestrian detectors 25-29 can be ignored

•    Queue detectors 18-20, 24 and 30 can be ignored

•    Bus detectors 21-22 can be ignored – these do not count north approach left turn movements

•    North approach left turn does not have a detector – make an assumption about the volume based on other lanes and movements

•    South approach left turn does not have a detector – make an assumption about the volume based on other lanes and movements

•    Some left/right turn and through movements are not distinguished – make an assumption about the volume proportions for each movement

SCATS SITE 3206

•    Pedestrian detectors 16, 21-29 can be ignored

•    Bus detectors 11 and 12 can be ignored

•    Clearance zone detectors 17-20 can be ignored

•    East departure detectors 15 and 14 can be ignored

•    Some left/right turn and through movements are not distinguished – make an assumption about the volume proportions for each movement

SCATS SITE 407

•    Select detectors relevant to intersection provided in brief only for your analysis

•    Pedestrian detectors 25-32 can be ignored

•    Bus detectors 20-22 can be ignored

•    Some left turn and through movements are not distinguished – make an assumption about the volume proportions for each movement

SCATS SITE 2206

•    Pedestrian detectors are 19 and 25-29 and can be ignored

•    Back of queue/ Bus loop detectors 13, 14, 17, and 18 can be ignored

•    Detector 12 can be ignored, it is equivalent to detector 9 + 15

•    West approach left turn does not have a detector – make an assumption about the volume based on other lanes and movements

•    Some left/right turn and through movements are not distinguished – make an assumption about the volume proportions for each movement

Appendix B

Example phase and signal cycle diagram

Phase A

Phase B

Phase C

Phase D

Intergreen # s

Intergreen # s

…